This invention relates, in general, to buckles for safety harnesses and in particular, to a lightweight, multiple-point, quick-release, safety buckle for body harnesses.
The use of safety belts, or harnesses, to restrain the human torso within a high-performance vehicle, e.g., in racing cars, or in high-performance aircraft, is well known in the art.
Typically, a plurality of cloth, leather or synthetic straps are adjustably-attached at one end to some part of the vehicle, such as the seat or floor, and are provided at their other ends with a end-connector, usually metal, which is releasably-engaged within a buckle device whose purpose it is to retain the connector ends together whereby a harness is formed of the straps to retain the vehicle's operator or passengers firmly within their seats until the mechanism of the buckle is actuated to release the ends of the straps, whereby the wearer of the harness is released from its hold.
The familiar embodiments of these restraining devices are the simple seat belts found on the seats of many commercial airliners having a pair of straps retained to the seat or floor of the aircraft, one strap having a releasable buckle at its outer end and the other a connector to engage within the buckle. This same familiar embodiment may be found in automobiles manufactured in this decade, often in conjunction with a third strap which passes across the chest of the driver to restrain the upper torso.
In yet another familiar embodiment of this apparatus which is often associated with high-performance vehicles such as racing-cars, aircraft or speed boats, a series of five straps are utilized to form the harness, in which two of the straps pass over the shoulders of the wearer, two pass about the wearer's waist, and a fifth strap passes through the legs and through the wearer's crotch, and all join at a buckle which may be located anywhere in a region from the wearer's waist up to the mid-point of the chest, which serves to restrain the wearer firmly within the seat of the vehicle during high-speed maneuvers and which also serves to help prevent injury to the wearer by collision of the wearer's body with the interior of the vehicle in the event of a crash.
In all of the familiar embodiments, it is desirable that the materials and construction of the apparatus be strong enough to withstand the high gravitational and/or inertial forces imposed upon the harness by the wearer's body during high-speed maneuvers or during a crash, yet be quickly-releasable, for both convenience and safety reasons which are obvious.
It is also further desirable that the overall apparatus be as light in weight and comfortable for the wearer as the degree of restraint imposed will permit.
Typically, the buckle part is retained at the end of one of the straps of the harness such that the buckle will remain with the vehicle when the wearer of the harness releases it for egress of the wearer from the vehicle. Further, it is not unusual for the buckle to be provided with means whereby the two shoulder straps may be selectively released while the three remaining straps are retained within the buckle to enable the wearer of the harness to lean forward, for example, to reach a remotely-located object or control.
Exemplary of such multiple-point, quick-release buckles are those disclosed in U.S. Pat. No. 2,899,732 to Cushman, U.S. Pat. No. 2,921,353, also to Cushman, and U.S. Pat. No. 3,825,979 to Jakob, and assigned to the present assignee.
A review of these references shows that they have in common, in addition to the above-referenced operational features, the following additional functional requirements. First, the ends of the straps must be retained within the buckle so as to withstand axial forces imparted to the straps by the wearer's body. This is typically accomplished by means of pawls which extend into apertures within the connector ends of the straps (usually metallic) which prevent a movement of the connector ends in an axial direction relative to the buckle unless and until the pawls are withdrawn from their respective apertures.
Second, the buckle must withstand rotational forces applied to the connector ends by the straps which would tend to rotate the connector ends about an axis through their planes within the buckle, and which would disengage the pawls from the belt end connectors, unless constrained to lie within the plane of the buckle. This is accomplished in the prior art by providing a pair of planar, rigid surfaces on the rear side of the cover of the buckle's housing and the front side of the rear member of the buckle's housing, respectively. Accordingly, it becomes necessary to make these portions of the buckle's housing, including the rotating actuator or handle, of a strong, rigid material, usually metal. Unfortunately, this results in a buckle that is heavy and expensive to machine or cast, and further, prevents the fabrication of major portions of the buckle from materials that are lighter in weight, inexpensive and easy to fabricate, such as thermosetting plastics or thermoplastics.
It is therefore an object of the present invention to provide a multiple-point, quick-release safety buckle for harnesses that is lighter in weight and incorporates more inexpensive materials which are also easier to fabricate, while incorporating all of the functional requirements of strength, safety, quickness of operation and convenience of the prior art.
It is a further object of the present invention to provide a safety buckle that is inexpensive to manufacture and easy to assemble, yet which retains the same safety and reliability features.
These objects are preferably accomplished by providing a buckle having a pair of spaced, parallel steel plates to receive the tongues of the straps' endconnectors therebetween and further, having one or more pawl-receiving apertures within the plates which permit the connector-engaging metallic pawls, which are pivotally-mounted on one of the steel plates, to rotate in and out of the tongue-retaining space, whereby the connectors are retained in, or released from, the buckle in the axial direction, and the connector ends are prevented from rotating by the presence of the pair of plates, and the whole affair may be contained within, and actuated by, lightweight, inexpensive plastic parts that are easy to fabricate.